1. Field of the Invention
This invention generally relates to a pointing device for controlling the positioning, movement and operation of a cursor on a display screen associated with a computer and, more particularly, to an integrated pointing device that is mountable to a printed circuit board that includes signal conditioning circuitry.
2. Description of the Related Art
Various devices are well known for controlling cursor movement over a display screen associated with a computer. One such device is a xe2x80x9cmousexe2x80x9d which has a ball mounted to its underside for contacting a horizontal surface and rolling therealong when manipulated by a computer operator. The X- and Y-axis components of movement are sensed and transmitted through a connecting cable to a serial input port of the computer. This signal to the computer is varied by the amount and direction of mouse ball movement, and causes a corresponding movement of the cursor on the display screen. Depending on the type of computer program in operation, the position of the cursor on a display screen may indicate a choice of computer commands on a menu associated with the computer program displayed on the display screen menu. Typically a pair of xe2x80x9cmousexe2x80x9d or xe2x80x9cclickxe2x80x9d buttons are located on the top of the mouse at the forward end thereof. The buttons permit a computer operator to enter a selection or other command to the computer (the command typically being shown by the position of the cursor on the displayed menu) upon pressing one or the other or both buttons, depending upon the software associated with the mouse. Such a device, which is separate from the computer console and keyboard, requires a connection to a computer port and a flat, horizontal supporting surface for proper operation. Furthermore, the computer operator must completely remove one hand from the computer keyboard in order to move the mouse and thus the cursor on the display screen and then reposition the hand again over the keys of the keyboard to resume data entry.
Another cursor controlling and signaling mechanism is a xe2x80x9cjoystickxe2x80x9d which, like the mouse, is completely separated from the computer console and keyboard. The joystick is typically an elongated, upright stick that extends upwardly from a base connected to the computer console by means of an electrical cable. The joystick is operated by tilting the upright stick in various directions to cause the cursor or other display element to move on the display screen in a direction and usually at a speed corresponding to the direction and pressure exerted on the stick by the computer operator. The operation of a joystick, however, frequently requires that both hands be moved from the computer keyboard, with one hand holding the base and the other hand manipulating the joystick. A xe2x80x9cclickxe2x80x9d button is usually located on the joystick. Although a mouse or joystick can be used with a portable xe2x80x9claptopxe2x80x9d or xe2x80x9cnotebookxe2x80x9d sized computer, such devices are cumbersome, since they must be carried separately and connected to the computer before use. Moreover, such devices are not suitable for operation during travel.
A xe2x80x9ctrackballxe2x80x9d is still another type of known cursor controlling device. This device, which in essence is an inverted mouse, includes a rotatable ball mounted within a housing. The ball is rotated by a finger, thumb or palm of the computer operator, and the X- and Y-components of movement are sensed and input into the computer with corresponding movement of the cursor across the display screen. xe2x80x9cMousexe2x80x9d or xe2x80x9cclickxe2x80x9d buttons are usually located on the trackball housing, although with some models a selection signal is input by pressing the xe2x80x9centerxe2x80x9d key on the standard keyboard. This type of pointing device has been somewhat useful with portable computers because it can be temporarily affixed to one side of the computer case for manipulation by one hand of the computer operator. However, although trackball devices can be removably mounted to the computer case, they still required attachment before use and removal after use and repositioning of the computer operator""s hand during use. It is also noted that some trackballs are built into the computer keyboard. Nonetheless, these trackball""s required a separate set of xe2x80x9cclickxe2x80x9d buttons for selection of items on the display monitor.
Manufactures of portable laptop computers, recognizing the need for placing the cursor controlling device in a permanent and more convenient location, have more recently installed a small, stubby button-like joystick at a central position on the computer keyboard, such as at the juncture of the xe2x80x9cg,xe2x80x9d xe2x80x9chxe2x80x9d and xe2x80x9cbxe2x80x9d keys of the standard xe2x80x9cQWERTYxe2x80x9d keyboard. The button-like joystick, also known as a pointing stick, is sensitive to lateral pressure, the amount and direction of which are sensed and input into the computer to cause movement of the cursor, with the speed and direction of cursor movement corresponding to the amount and direction of pressure on the pointing stick. In order to select items on the display screen, upwardly extending xe2x80x9cmousexe2x80x9d or xe2x80x9cclickxe2x80x9d buttons must be provided somewhere on the computer, typically at a location remote from the pointing stick.
While the pointing stick systems in use are of great value, there remains some shortcomings. One common issue is the susceptibility of the low-level output from the pointing stick to various electromagnetic interference within the computer. A further shortcoming is the size and space in the keyboard required in order to place signal conditioning circuitry with the pointing stick device.
It is a feature of the present invention to provide a pointing stick for controlling cursor movement on a display screen of a computer system.
It is a further feature of the present invention to provide an integrated pointing stick device for controlling cursor movement on a display screen of a computer system that integrates electronic circuitry into the pointing stick package.
According to one embodiment of the invention, an integrated, surface-mount pointing device for controlling the movement of an object on a display screen, comprises a base member; a shaft having a first end and a second end, with the first end mounted in the base member; a first sensor mounted on the shaft for sensing the amount of strain in the shaft in response to an applied force on the shaft in at least a first direction; and a first pair of spaced electrical leads extending at least partially through the base member. Each electrical lead has an inner terminal end electrically connected to the first sensor and an outer terminal end extending outwardly of the base member. The outer terminal ends are mounted to a printed circuit board. Additional electronics, for example signal conditioning circuitry, are mounted beneath the base.
According to a further embodiment of the invention, a keyboard for entering data in an information system comprises at least two keys located on the keyboard; a shaft located between the at least two keys and extending upward toward a top surface of the keys; a first sensor mounted on the shaft for sensing the amount of strain in the shaft in response to an applied force on the shaft in at least a first direction; a circuit board mounted in the keyboard in the vicinity of the two keys; a base member positioned below the at least two keys, with a lower end of the shaft being mounted in the base member; and a first pair of spaced electrical leads extending at least partially through the base member. Each electrical lead has an inner terminal end electrically connected to the first sensor and an outer terminal end extending outwardly of the base member. Electronic circuitry is mounted between the printed circuit board and the base member. The outer terminal ends of the first pair of leads are mounted on a surface of the circuit board.
There has thus been outlined the more important features of the invention so that the detailed description thereof that follows may be better understood, and so that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter which will form the subject matter of the appended claims. Those skilled in the art will appreciate that the preferred embodiment may readily be used as of basis for designing other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims are regarded as including such equivalent constructions since they do not depart from the spirit and scope of the present invention.